This application claims the priority of Korean Patent Application No. 2003-87250, filed on Dec. 3, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a protocol stack in accordance with an OSI (open system interconnection) reference model, and more particularly, to a data processing apparatus and method.
2. Description of the Related Art
FIG. 1 is a view illustrating a conventional protocol stack. The conventional protocol stack comprises a plurality of interfaces 11, 12, 13, and 14, an Internet protocol (IP) layer 2, a Transmission control protocol/user datagram protocol (TCP/UDP) layer 3, and a plurality of application layers 41, 42, 43, and 44.
The plurality of interfaces 11, 12, 13, and 14 are link layers in an open system interconnection (OSI) reference model and, for example, include a Local area network (LAN) interface 11, an IEEE (Institute of Electrical and Electronics Engineers) 1394 interface 12, a Universal serial bus (USB) interface 13, and a Wireless local area network (WLAN) interface 14. Each interface is a hardware component functioning as a link for physically connecting apparatuses on which the protocol stack shown in FIG. 1 is mounted in various networks such as LANs, IEEE 1394 networks, USB networks, and WLANs.
The IP layer 2 is a network layer in the OSI reference model. In the 1P layer 2, data received through the networks are integrated. In other words, when the data are received through the networks, an operating system of an apparatus on which the protocol stack shown in FIG. 1 is mounted transports an interrupt signal to network device drivers. The network device drivers receiving the interrupt signal start to process the data in accordance with the Internet protocol. Since the data are processed in a software manner, there is a problem that other tasks may be delayed in a processor of an apparatus on which the protocol stack shown in FIG. 1 is mounted. When a plurality of data are processed in a software manner in accordance with an IP protocol in network device drivers, since the network device drivers have different task configurations, the data received through the networks are replicated and stored in a memory. When the data is processed, “task switching” is performed. That is, task configuration for the data replicated and stored in the memory is formed and the data is processed. Since an additional time interval is required to replicate and store the data in the memory and to form the task configuration, there exists another problem involving delay. The delay may destroy isochronism for a multimedia data processing procedure.
The data processed in the IP layer 2 is transported to a TCP/UDP layer 3. Since the data are processed in the software manner in the TCP/UDP layer 3, the aforementioned problems still exist. The data processed in the TCP/UDP layer 3 is transported to and processed in application layers 41, 42, 43, and 44.